Throughout this disclosure, the terms dishes and dishware will be considered to include water washable kitchenware, dishware, tableware, flatware, dinnerware, hollowware, utensils and the like commonly used for preparing, cooking, serving and consuming meals. The terms mobile and nomadic will refer to an apparatus that is self-contained, has a relatively small foot print, is skid-mounted or trailer-mounted, is easy to assemble and disassemble and can be moved from one location to another. The terms mass and high volume will refer to an apparatus that is designed and constructed to operate in continuous or batch mode to serve a large group of people in a small community, a population pocket or a remote campsite, mess hall, cafeteria, aboard ship and the like. The use of this terminology is for simplicity in explaining the applicability of the enclosed apparatus and methods, unless specifically excepted.
Dishware cleaning is an important function in preventing the proliferation of potentially harmful bacteria, preventing the attraction of a variety of undesirable creatures, such as bugs, roaches, mice and rats, enhancing the aesthetics of dishware and for other health, cultural or appearance purposes. Water and detergent have frequently been the method of cleaning dishware. However, water is increasingly in short supply in many places in the world and detergent is relatively costly, can be difficult to transport, and has potential environmental affects. Furthermore, isolated population pockets and remote campsites as well as arid and desert regions lack ample freshwater resources and wastewater processing facilities. Ocean- and sea-going marine vessels have limited fresh water supply and harsh restrictions on disposal of gray water and black water at sea.
Sand and silica have also been a media of choice for scrubbing and cleaning kitchenware and dishware, particularly for camping dishware. Sand is still used today by nomads and scouts to remove stubborn grease and burned and hardened food particles from scorched surfaces, and to remove soot accumulating on pots and pans used for cooking on open fires, especially in situations where there is no detergent and very little water. Sand cleaning provides a shine on the surface of utensils and cookware, preserving the surface luster of copper and stainless steel pots and pans. Indeed, some detergents contain abrasive particles for washing highly soiled dishes and stained and grimy clothes. Some specialty soap may also contain abrasive particles for cleaning skin soiled by hard-to-remove lubricants and crude oil.
Thus, fine sand and silica particles may be used in cleaning cookware, kitchenware and tableware whenever water and detergent are not available or do not provide the desired cleanliness of surfaces without extensive waste of resources and effort.
In rugged areas inhabited by nomads, remote desert pockets of population, arid land and wasteland, people are crowded around very limited water sources, where utility services are often beyond reach. Such areas are often the preferred locations for military and civilian camps. In these areas, cleaning cookware and food service ware is difficult and the logistics of constructing water wasteful and detergent demanding dishwashing systems with adequate plumbing are rather complex.
To reduce the amount of water required to clean pots and pans in the battlefield, Muller et al. proposed a chemical sanitation system that effectively cleaned and sanitized pots and pans at cold water temperatures, 15 to 20 degrees Celsius, as reported in Wayne S. Muller et al., Chemical Sanitation System for Pots and Pans in Field Operations, report #NATICK/TR-89/020, U.S. Army Natick Research, Development, and Engineering Center, Natick, Mass. (February 1989). While effective at sanitizing, this system had difficulty removing grease at this temperature range. At this time, no commercial product or combination of products available can effectively clean all types of food residue from pots and pans at these temperatures.
McCormick, et al. developed a procedure to clean and sanitize kitchenware in ambient cold water during emergency situations, in which dirty pots, pans, and kitchen utensils could be successfully cleaned and degreased, starting by hand-scrubbing the kitchenware in a sink containing a 5% solution of a commercial cleaner/degreaser at 15 degrees Celsius, as reported by Neil G. McCormick and R. G. Flaig, Cold Water Cleaning and Sanitizing of Kitchenware in the Field, report #NATICK/TR-90/013, U.S. Army Natick Research Development, and Engineering Center, Natick, Mass. (December 1989). The scrubbed article was then rinsed in a sink filled with water held at 15 degrees Celsius and sanitized in a third sink containing a 15 degrees Celsius solution of a commercial quaternary ammonium sanitizing agent. Results from swab tests performed on processed articles showed the number of bacteria to be well below the permissible level, if not completely absent. The procedure was judged highly successful in cleaning, degreasing and sanitizing kitchenware in cold water. This same procedure also successfully cleaned and sanitized individual mess gear in a field test situation using water at 20 degrees Celsius. However, using such a chemical procedure creates pollution problems with the disposal of gray water and the chemicals used to clean the kitchenware.
Certain solvents, along with a surface wetting agent, may replace water detergent in a process similar to dry-cleaning clothing. Furthermore, some solvents used in dry-cleaning, such as tetrachloroethylene (TCE) and Stoddard solvent, can remove various types of stains and grease and thus may have potential uses for cleaning dishware. Nash et al. found that certain surfactants are especially useful for degreasing and removal of oils as reported by J. Nash et al., Surfactant-Enhanced in Situ Soils Washing, report #AFESC/ESL-TR87-18, Engineering and Services Lab, Air Force Engineering and Services Center, Tyndall AFB, Fl. (1987). As these chemicals are of relatively small volume relative to the amount of water used in traditional processes, such chemicals would be fairly easy to store and reusable after filtering.
Accordingly, there is a need in desert population centers, either temporary or permanent, for a dishwashing system that is easy to assemble and to disassemble and provides service for large groups on as-needed basis, while preserving limited vital resources such as water, causing no pollution to those resources, and requiring very little supply of consumables.
In order to understand the background of dishwashing better, hereinbelow are a variety of situations concerns associated with cleaning in general and cleaning dishes specifically, along with current techniques and needs.